The incident occurred at 2,000 ft, about eight miles south west of Kennedy International Airport as one plane from London was preparing to land while another took off for London.

The planes, travelling at 200 mph, passed just 800ft above the other and just under a mile apart laterally.

US Federal Aviation Administration (FAA) regulations say that planes must be separated by a minimum of 1,000 vertical feet and three miles laterally.

Visual contact

The FAA is investigating the "operational error", which occurred on Thursday afternoon near the busy New York airport.

A British Airways spokesman said the incident was a "non-event," adding that pilots of both aircraft had visual contact and were fully aware of the situation.

Daily trips

Phil Barbello, president of the National Association of Air Traffic Controllers in New York said: "This wasn't a real close one.

"It was less than standard separation but it wasn't like anything that would be critically dangerous."

British Airways and Air France are the only scheduled airlines flying the Concorde in the United States.

British Airways flies two daily round trips between London and New York, while Air France operates a daily round trip between Paris and New York.

Concorde flies above turbulence at nearly 60,000 ft (18,000 m), crossing the Atlantic in about 3½ hours, less than half that of subsonic jets.